Add chrome.searchEnginesPrivate API and Search Settings page.

chrome/common/extensions/api/_permission_features.json

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This features file defines permissions for extension APIs implemented
 // under src/chrome.
 // See extensions/common/features/* to understand this file, in particular
 // feature.h, simple_feature.h, and base_feature_provider.h.
 
 // To add a new whitelisted ID, SHA-1 it and force it to uppercase. In Bash:
@@ skipping 851 matching lines @@
       "A74A4D44C7CFCD8844830E6140C8D763E12DD8F3",  // Google Talk beta
       "E7E2461CE072DF036CF9592740196159E2D7C089",  // Google Talk alpha
       "312745D9BF916161191143F6490085EEA0434997"   // Google Talk debug
     ]
   },
   "screenlockPrivate": {
     "channel": "stable",
     "extension_types": ["platform_app"],
     "location": "component"
   },
+  "searchEnginesPrivate": {
+    "channel": "trunk",
+    "extension_types": ["extension", "platform_app"],
+    "location": "component"
+  },
   "screensaver": {
     "channel": "stable",
     "extension_types": ["legacy_packaged_app", "hosted_app", "platform_app"]
   },
   "sessions": {
     "channel": "stable",
     "extension_types": ["extension", "legacy_packaged_app"]
   },
   "settingsPrivate": {
     "channel": "trunk",
@@ skipping 105 matching lines @@
   },
   "webstorePrivate": {
     "channel": "stable",
     "extension_types": ["extension", "legacy_packaged_app", "hosted_app"],
     "whitelist": [
       "B44D08FD98F1523ED5837D78D0A606EA9D6206E5",  // Web Store
       "2653F6F6C39BC6EEBD36A09AFB92A19782FF7EB4"   // Enterprise Web Store
     ]
   }
 }